Black smoke when climbing?

[FlyingBarney]

I was on a trip last week, part of which took me from Portland to Bend, climbing the area of Mt. Hood. Strangely, I noticed quite a bit of black smoke from the exhaust when climbing. Only when climbing. It never happened before, and stopped when the climb completed.

About a week before the trip, I did the usual oil'n'filters at CVI, and everything was fine. Since it got warmer, I am now filling the tank with B20 (20% biodiesel), yet in the US the last tank before the climb was regular diesel. I wonder whether any of it might be related, or whether there is something else I need to look into.

Thanks,
Simon

[mararmeisto]

These will smoke when pushed, just the nature of the mechanical fuel injection system: it simply dumps more fuel in (not finely adjusted like electronic fuel injection). The smoking is little different than a gasoline engine, you just can't see the excess/unburnt fuel coming out of the tailpipe of a gasoline engine.

That being said, if you back off the accelerator just a bit (until the smoke stops, watch in the side mirror), you'll maintain most of your speed as you climb. Shifting down will help a bit too, or dropping it out of overdrive (if you've an automatic).

Final thing to keep in mind: it's only an 85hp engine. It'll climb all day, just not at 120km/h!

[jrman]

Agree with Maremeisto....just back from Okanagan trip. IP rebuilt in November 2008 - bus runs awesome around town. Lots of smoke on big hills in high elevation heading into and out of the Okanagan. Now, back home and around town things are back to normal - slight smoke under stress on hills - much less than compared to the high elevation heading into places like Manning Park etc. I'm sure that elevation plays a role in these machines that don't have any oxygen v.s. fuel & other sensors of the modern diesels.

[marsgal42]

Old-school diesel = smoke when climbing.

The amount of fuel going in to the cylinders, as specified by your right foot, is greater than what the engine load and RPM actually need. The result is excess fuel going down the tailpipe, partially burnt as black smoke.

Look at your Delica's injector pump. There is a barometric doodad for the turbo boost, but that's about it.

...laura

[Rattlenbang]

whoops, wrong thread; pardon me.

[nxski]

I try to keep it at 3000-3500 RPM on hills so as not to lug and overheat the engine. A pyro is a useful tool to have for this as well.

[glenn]

Wow, that was a blast from the past . . . 2009 eh?

Yes, like mararmeisto said so many years ago, back off on the throttle and keep the revs up - not for the turbo, but to keep the cool air over the rad. If you haven't realized this yet, these engines are only 85 hp when new, and they are prone to overheating and the heads are prone to cracking. It's their Achilles heal so to speak, so be careful - let the fully loaded semis pass you on hills. You can overtake farm tractors occasionally.